Work place anxiety

Todays not a great day for me. My workplace is extremely understaffed and Im seriously struggling with the amount of stress thats been piled onto me. Just earlier I was pulled on reducing the price of an item that was identical to what the customer showed was on the online store.

We are told the limit that we are allowed to reduce the total by is $50. This item wasnt even reduced by 15 but still I was questioned. I had to repeat my reasoning 3 times to the manager and even had to show her the online price cos she simply wasnt understanding what I was saying.

Communication isnt my strongest point, I can blame my social anxiety for that but now, I dont even know how Im gonna last the next 6hours of this shift cos my hands are shaking terribly and my heart is pumping hard... hopefully I calm down before my break ends...